Hi, There are blood tests which are used to detect the presence of hepatitis A in your body. A sample of blood is taken, usually from a vein in your arm, and sent to a laboratory for testing. Some of the tests done for hepatitis A are as follows. The HAV IgM antibody test detects the first antibody produced by the body when it is exposed to hepatitis A. This test is used to detect early or recent infections and to diagnose the disease in people with symptoms of acute hepatitis. The HAV IgG test detects the IgG antibodies that develop later in the course of the disease. IgG antibodies remain present for many years, usually for life, providing protection against recurrent infection by the same virus. The IgG test is used to detect past HAV infections and may occasionally be used to determine if an individual has developed immunity from a previous infection (immune status), in which case a vaccine is not necessary. The total HAV antibody test detects both IgM and IgG antibodies and thus may be used to identify both current and past infections. This test will also be positive after receiving the vaccine, so sometimes it may be used to determine whether a person has developed immunity after vaccination, though this practice is not advised. In acute hepatitis, other tests such as bilirubin, liver panel, ALT, and AST may be performed with viral hepatitis tests to help diagnose the condition. Ultrasound scan abdomen is done if required.